Mass spectrometry microstructure characterization

The THM reaction linked to GC, GC/mass spectrometry (MS), and MS has been successfully applied to the chemical characterization of a number of synthetic and natural products, including resins, lipids, waxes, wood products, soil sediments, and microorganisms. This technique is also very effective for the detailed characterization of the synthetic polymeric materials, especially the condensation polymers, such as polyesters and polycarbonates, because many simplified pyrograms are usually obtained that consist of peaks of methyl derivatives from the constituents of the polymer samples almost quantitatively. In this chapter, the instrumental and methodological aspects of Py-GC in the presence of the organic alkali are briefly described, and then some typical applications to the precise compositional analyses and microstructural elucidation inclusive of the intractable cross-linking structures for various condensation type polymeric materials are discussed. 

When the surface of a solid is bombarded by energetic primary particles, usually, electrons, ions, neutrals, or photons, and secondary particles are emitted. The secondary particles are mainly electrons, neutral species, atoms or molecules, atomic and cluster ions. The majority of secondary particles are neutral species. The secondary ion mass spectrometry (SIMS) is a kind of mass spectrometry, where only secondary ions are detected and analyzed by the mass spectrometer. The process yields a mass spectrum of a surface and thus the method enables a detailed chemical analysis of a surface or solid. SIMS is such a powerful technique of surface analysis and microstructural characterization of solids that a very low primary particle flux density of 1 nA/cm or even less can generate spectral data in a timescale, which is very short compared to the lifetime of the surface layer. SIMS is particularly well known for its outstanding sensitivity of chemical and isotopic detection. Quantitative or semiquantitative analysis can... 

The microstructure of the obtained copolymers is expected to bring useful information on the polymerization mechanisms. Advanced polymer characterization by SEC, NMR and ESI or MALDI-TOF mass spectrometry are commonly combined for elucidating copolymerization... 

By far the largest, most successful applications of PGC have been to the characterization of synthetic polymer microstructure. PGCs of these compounds yield information such as monomer identity and content, purity, and presence of additives. PGC is even more powerful for solving these types of problems when coupled with spectroscopic detectors. For example, Sahota et al. (48) showed that single-step PGC coupled with mass spectrometry could be used to measure the DNA content of cultnred mammalian cells. 

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